And abnold



kA Usriiiv H. non, or NEW YORK,l Aim sfraans ARNOLD W. LENDEROTH, or s'rAPLEToN, New

YORK. v

MAGNETIC D-ETECTOR`APPARATUS FOR RAILWAYS.

ifi 93,7 va.

To all whom t may concern'. y

Be it known that we, AUSTEN H. FOX and ARNOLD lV. Lnnninio'iii, citizens ,of the United States, residing at- Neiv' York city, in the rounty and State of New York, and at Stapleton, in the county off Richmond and State otv New York, respectively, have invented certain new and useful Improvements in Magnetic Detector Apparatus-for vRailways, of which thefollowing is a speciiication. 'n

This invention relates to means for con trolling-ory giving an indication on a' rail-j way vehicle hy varying the condition of the roadway, and it especially relates to-apparatus of this character vusing magnetic c0mmunication between the vehicle and the roadway. i, l

Our present invention may be embodied as an improvement on the apparatus described in the Fox .Patent No. 1,088,811', dated March 3, 191i, and itsprincipal objects are', first', in

Aconnection with the detector appai,atus, to

diminish the amount of energy required in `the car magnet which cooperates with the' armature rail and reduce tliespace occupied for a magnet of given sti'engtlito provide a inagnet-operated sivitcli which shall. be prooi' against vibration, to avoid heavy springs or counterweights, and to overcome itlie disturbing effects on ythe action of the ma gnet caused by side play o1: seekingof the truck; secondly, ,to provide means tor perpetuating the indications given on a moving unit by a self-restoring car magnet, after the latter has passed a control point; thirdly,

to furnish means for automatically indicating on the moving unit the passage of a control point Where the signal oi' control apparatus is set fora clear track, where if not set for clear, a danger 'indication would be given; ,and fourtlily, to provide a suitable mode of combining-the' last-named function and the normal` danger-indicating function of the detector in asingle instrumentality. Of tlie accompanying drawings, Figurel represents a diagrammatic view of an em` bodiment of the invention-adapted to accomplish 'the first andv second objects abovenamed. Fig. 2 represents a longitudinal sec-V tion and elevation showing the detectorand Specification of Letters Patent.

Referring at `first to Figs 1 to l,k 10 represents one of the running rails cfa railway track of wliich'11,`l1 are ordinary magnetic steel sections and 12 is an interposed rail sectioncomposed of a'suitable non-magnetic material such as manganese-steel. 18 is a magnetic lay-passing bar or rail placed along side of the `manganesesteel section 12, and adapted to be moved under the control of the signal apparatus or other routside agency into and out of a position where it will op- ,eia'tively influence thefdetector` magnet. The

latter is carried in a casing kle! suitably supportedon the truck .of the engine or. other railway vehicle `whose'wheels are indicated at e9, and in' this instance it comprises a magnet composedof two parallel diametri cally-disp0sed spools or windings, `15 mount-A Iatentednug.. 8, 1916. Application aiea August s, 1912. `seria; n. 713,965.

edon coreswhich have magnetic pole-pieces- 16 at their lower ends over the running rail, .and are connected ,at their upper ends by 4a.

magnetic" yoke 17. This magnet is mounted to turn ona longitudinal axis on trunnions 18 mounted instandards 19,. the said axis.

passing as nearlyy as possible through the center of gravityk of the mass soas to balance the` latter against vibration," and a light spring 20 is provided for carrying the polepieces 16 lupv'vardly and outwardly in a circular arc away from the running rail when the magnet 'reaches a magnetic rgap in the latter. One of the trunninns `18 andstandard 19 are provided With coperating'istop inem-- bers 21,122 to keep the polepieces of the magnet, when the la .ter are drawn down,`out

-ofcontact Withtlie ottoin ofcasing 14', and

the planeoic contact, of tliesestop members is f' kc lank arins -l-T.

magnetic and non-magnetic sections ofthe running` rail at the two ends of the latter, for a purpose hereinafter describedtvthese lix'ed sectionsbeing interrupted by a gap adapted to be magnetically closed or opened by a movable armature section Mathe latter .in-this case being'niounted to swing hori- ZontalljyY into and out ofthe gap on apair of 4S is z portion ot la noninagneti'c casing' .serving to cover and protet-t the movable bar 40. l-S) is a plate carv ried on pins 49h on an equalizer-bar 40e -of and fixed therein, the polepie'ces and cores through the hollow core 55, theres" -only being movable and made magnets by induction. There are two sets ot pole-pieces 53, 54, the-two innermost ones 53 bourg, at-- taohed to the ends of aholl'ow soft-iron .'c'ore 5o which passes throughthecoil 52,1 -arid the two outer ones 5t beingl attached to the ends of a softar'on rod or core 15G which passes cores having`antifriction bearings s .fin the plates or standards 57,-58. "'lhese plates or standards, between which' the osiil-` latory pole-pieces are located, are connected' by tiesrods 101, Aand the two plates 57, bel" tween. which the coil 52 is located, are con! neeted yby other tie-rods 102.- -The easing 14 is composed of a tubular bodyl 103 and4 two pyralnidal endspieoes or heads 104 connected to the. plates 58 by largejsingle screws or bolts 105.

, .The respective pole-pieces 54, whose -upper ends are provided with non-magnetic -v eounterweights 53"- 541, slant downwardly in. opposite'direotions so as to straddle the l space above the head ofthe running; rail,

the pole-pieces 53 being' principally' under theV intlueIQwf the inner side of said rail While the l pole-pieces 54 are principally under the'inliiience of the outer-sale ofthe "running1 rail andthe liv-passing rail. There-` by the effects of lateral seeking of theI truck are, taken care of, because one or'the other of the two sets of pole-pieces will always be attracted when over aniagnetio part ot the running rail. Obviously this torni 'ot' def. tector `could bei substituted `for the EtorniA shown in I `igsnV 1 to #for merely indicating;q

the presence or absence of the danger con-A dition on reaching a control point,tl1o yoircuits and 'switches being @suitablyy arranged so that the' release of both sets of pole-pieces would be required to give the danger 1nd1.

*the track apparatus is yset oijrlear attheV 'would be 'giren it' the apparatus were. set! 4at danger. The additional 'tunetiolneould he performed with an independent rdetec of the inagnet are ot' like polarity, and there# .for each other and both. pole-pieces tend to vbe `drawn down fardly. The downward .9g nim-'ement of the pole-p1eees 51 is Alimited by switches in the n'ianner hereinafter .defi

seribeth but'as we also deslre. to have Vgore and pole-pieces 53,` said switche ,construotiom the pole-piece having attaehed` to it a .segn'ienta'l insulating,r disk Gileari ration, as ,we will'uiore particularly point@v L out hereinafter .in describing Fig. 9'. The,y additional magnetic detector nieinbcr 'or polepieres however, lnayvalso, as will now;j 1 be pointedy out in connection with Fig.v 5,4m serveto give apositive el lar indication when control point where da danger indieatioir toiVw-itluult departing; from our invention but we find that the two tunetions may becombined with advantage, in a single` instru mentality. i

The two pole-pieces. 54 at the same end.

fo're tend to repeleaeh other or spread tol:

diametrically opposite positions it' no exter nal armature is present below them, butwa' when the magnetic running rail .is present 'CYL the flux through said rail and the ple"- pieees-overcolnes the repulsion of the latter fixed and movable stop inen'ibers 59-5 l60.` ,(pp,

and Tlf, andthat ofthe `pole-pieces limited by'f'inetl` and niovablefstop nienibers 01,02, the contacting` stop faces being vertical'. "flie'repulsion between the pole-pieces sufficient to produce'a danger indication by the opening of both detectorfy the 16o pole-pieces actlseparately, it is preferred l to employ' light springs 03, 64: for retract-l ingsa-id pole-pieces, and adjustable bacle stopsy G5, 00 todiniit the retraetingnieve-y nient.' 'Also these springsA allow testing'of 105 the apparatus for derangeinent of the mainv i energizingcircuit 24, 25 ot the detector coil",r for it' this circuit is broken and the Sigi'ial circuits herehiafter described vare intact, they closure of thehand switch 100 willfgive` a danger indication where otherwise asafe` indication would appear. i

lfgis. il and 7 show both Visets of polepieces in their retracted positions, and Fig shows the pole-piecesv 5t drawn down by.y theV liv-passing rail 46.

07 is a` switch operated bythe movemen of the coi-'c 56 and pole pieces 5l, and (3S is.l a switch operated bv the movement of the being closed whenthe respective pole-piecev` are tlowjrnandy opened when .the pole-pieces are ,up.` .The two switches are of similar dental opening of the circuit by jarring. 130

lll

E23 representethe dynamo or source of .current on the vehicle and Q4, 25 are the the bridging switch contact 29 and the fixed contacts 35.

75 is a solenoid the raising of Whose core stern 76 causes a green glass target 77 to pass between a white lamp 78 anda white glass spectacle 79 to Igive the clear indication at a control point. The two lamps 27 and 78 are in series across the mains 24', .25 through wires 80, 8l, 82. Fig. 8 represents the arrangement of parts for the red signal .which is also suitable for the green' signal, there being preferably a white fixed surface 83 back of the lamp to show red, green or White by reflected light even if the lamps should be out.

8l is a sustaining solenoid whose core stem 85 is connected with that of the solenoid 75 and carries a bridging Contact 86 cooperating with fixed contacts87 to hold the circuit ofsolenoid 84 closed.

Current passes from the main 24 by Way ot a wire 88 to the solenoid 31 and from ythence. by wire 89,` switch contacts 35, 29,

and wire 90 to wires 01, 92 which connect the brushes 72 ot1 the two detector switches 67, 68. For convenience the switch 68 may be termed the main switch, and switch 67 the byLpass switch. Since they are both in series with the solenoid 3l and in parallel with each other it is evident that the circuit has to be broken at both switches before the solenoid 31 will drop its target and give a danger indication. The current from brush 7l of thc main switch 68 passes by way. of wire 93 through a resistance 94 and thence through a return wire 95 to the main 25, and also passes in parallel through wire 96, solenoidi, `switchlmembers 86, S7, and wire 97 to the return-wire,

this branch circuit containing a push-button switch 98 'which is normally closed. The resistivity of the solenoid 84 'is less than that-of the resistance 94. Current passes from the Abrush 7 1 of the by-pass switch 67 by way of wire 99 through the solenoid 75, and. returns'by Wires 100 and 95. The re sistivity of the solenoid 75 Vis greater than that of the resistance 94.

In the operation of this form of our invention it may' be assumed that the detector is over a magnetic rail section 11 and the core of solenoid 31 has been manually raised to close the switch 29, The pole-pieces 53 will be held down toward the rail, and the main switch 68 will thereby be held closed so that current passes through the solenoid 31-and the latter tends to hold its core and the red target 73 elevated. This current also passes through the' resistance 94. If the green target 77 has previously been dropped, i

the circuit of solenoid 84: will be broken at they switch 86, 87. The other pole-pieces 54 may or may not be held down, depending` somewhat upon the lateral seeking of the truck or 'the presence of external iron.

When the detector reaches a` control point,

the pole-pieces 54 are drawn""or kept. down by the advance fixed section 44 of the by` passing rail, and the by-pass switch 67 is), thereby held closed.. This completes the branch circuit through the solenoid 7 5, but' since the latter is of greater Yresistivity than the resistance 94 in parallel therewith by,

Way of the main switch 68, the current flows principally by the latter path and the green soon as the polepieces 53 come over the nonmagnetic rail section '12 they are released Yand-the circuit through the main switch 68- and resistance 94 is broken. Solenoid 7 5 will' ltarget is not immediately raised. Butias 'i the` speedfof the trein and the amountso overlap which 44 has upon the non-magnetic section 12. If 46 has been moved into its operative position, the clear signal only,

given by the elevation of the target 7 7, will show. The circuit through the solenoid-31 for the danger signal remains intact through the lay-pass switch 67', and the red target 3 isnot dropped.` The' elevation of the green target completes the circuit through the,

switch 86, 87 and solenoid 84, and this condition persists after the control point is passed and the circuit through the' xn'ain switch 68 and resistance 9% hasbeen restored, since the latters resistivity is' greater than that of solenoid 84. The green target may `be dropped by the engineerbreaking the circuit through S'l by pushing theswltch 98. f The purpose. of the overlapping or iixfed armature section 44 is to; iusure Vthat the,

pole-pieces 54, which might `be up through sideseeking of the truck,ishall be, brought down before the pole-pieces 53 'have been released, so that 54 shall `tie-prepared to -give a green signal if the filler 46 is insthe gap.

The overlapping fixed` section 45 serves a' similar purpose 1n holding closed the switch 67 ,until the switch 68 is closed, and thus" avoiding a false danger indication.

If the movable magnetic bar 46 is. out of the gap between 44 and i5 when the detector passes over the non-magnetic rail sec-- tion 12, both sets of pole-pieces and 54C will be releasedand-both of theA switches 67 and 68 will be opened. This breaks the circuit of solenoid 31 and the :'ed target 'Zdwiil dropf, giving a danger indication. T heymw mentary impulse through'the cleiirsw'nal solenoid 75 which` precedes the danger sig- 4 l0 nal is not' of suiiici'ent duration 'to mislead .20 4control of the vehicle as well asthe giving of a visual ory other signal. For example;

in Fig. 9, 107` may representthe train-pipe of an air-brake system, .and 108an outlety valve thereforl whichwhen o'penallows thev train-pipe pressure to become reduced so as 4to apply the brakes in a well-known manner. 109 is a solenoid connected in a circuit 24, 110, 110a7 111, 25 with the dynamo 23, which circuit also includes the two detector switches 07, GS kin parallel with eachother, theopening of both switches, in a manner which will be understood from the previous description being required 'to' denergize the solenoid 109. The 'solenoid has two alined magnetic cores or armatures 112, 113, connected with each other by a non-mag-v netic stem 11117` and connected with valve 108. 115, and 116 are two movable bridgingr 'contacts carried by the solenoid core struc- 40 ture, and 117, 118 are two sets of fixed contacts whose members are connected respectively to the wires 111 and 1101. \119 isf'a f spring to hold the valve 108 closed. When thev circuit of solenoid 109 is closed by the switches 67, 68, the valve 108 is held closed by theattraction of the solenoid for core Y. 112, andalso by` the spring 119 (or addi' 'tionally, 'or .instead by gravity if the solenoid is placed vertically). When `a control point with an open gap in its ley-passing rail is reached, the opening of the switches 67 (38 breaks the circuitof the solenoid, core 112 is reieased; the air-pressure forces and holds 'valves 108 open againstthepressure l of spring 11%), andthe switch-116, 118 wil/l' be closed. The coming again of the detector over a vmagnetic rail-section restores the circuit of solenoid 109 and the attraction of the llatter for its core 113 holds said circuit' closed at the switch 116, 118 until tl. engineer breaks the circuit" momentarilyat a push-button switch 120. This allows the core structureI to retii-rn-, closing the'circuit again at switch 115, 11T and when ythe pushan armature rail, of a d Aector carried by a button switch is closed the valve will again be held closed by n'iagnei'ic attraction and spring pressure. This simplified circuit arrangement could obviously bc used also with a lnerevisual or other-signal. The arrangement of air-valve, solenoid andV core-con.- nected switches shown in Fig. 9 is not herein claimed as a separate instrumentality.r i

` Vle prefer in practice to equip the vehicle l with a detector on each side so as to run in either direction, and may provide an automatic reversing switch such as those used in axle-lighting systems for automatically cut ting'out either detector according tothe di-. rectionof movement of the vehicle, but for `thesake of simplicity vhave omitted such derices from the illustration. f lVeclairms".

' 1. In a railwaycontrol or signal system, the -combination of a rail-way having an` armature in the roadway thereof, arailway vehicle, and a 'detector carriedby said vehicle and including a magnet member Apivoted to oscillate toward and from said armature, transversely of the direction of vehicle travel. 90

2. The combination of a running rail hav'- `V ing magnetic andnon-magnetic sections, a detector magnet carried by 'a railway vehicle and pivoted .to oscilla-te in a vertical plane transverse to/'the line of said rail under control of the latter, and means controlled by said magnet for giving anindication on I the Vehicle. y

8. The combination wi a railway having lvehicle above saidf` rail and comprising a magnet member pivpted on an axis parallel to the rail passing substantially through the center of gravity of said magnet` member, the latter having pole-pieces adapted to be attracted downwardly toward the rail, and a switch operated by the movementy ot' said magnet member.`

4. The combination with a railway having an armaturefraih of a detector mounted to travel above said rail and comprising a gravity-balanced magnet pivotedto swing in a piane transverse tothe line of travel, a spring forretracting said magnetrand a switch operated Aby the magnet.

y5. The combination with a'. railway having anarmature rail, of a detector mount-ed to travel above said rail and comprising a magnet4 member pivoted to swing itspole toward and from the rail, and stop members con- 1 tactingin a substantially vertical .plane for limiting the rail-approaching. movement of said magnet member.

6.. The combination with a raiiwa-y having .an armature rail,foffa detector mounted to travel above said rail and comprising a magnet member'movableby'the iniiuence of the f mib-and a switch controlled by said magnet meniber and having dupli x,ate switclrpoints oppositely responsive to shocks.

7. The combination with a railway having an armature rail, ot a detector mounted to travel above said rail and comprising a 1nagnet member niovableby the influence oi' the rail, a circuit having a movable switchcontact on one side thereof.V actuated by said magi'ietancn'iber, and duplicate yielding brushes on the other side of the circuit embracing said movable contact between them and oppositely movable thcreagainst.

S. The coiiiliiination oi' a railway having a running rail composed of magnetic and nonmagnetic sections, a railway' vehicle, a magnet carried by the vehicle and adapted to be released by encountering a non-magnetic rail section and automatically attracted again-on reaching a magnetic rail section, a circuit controlled by said magnet and having an indicating device adapted to be actuated when the magnet reaches a noirmagnetic section, and means controlled by said device for retaining it in its indicating condition after the magnet has been,reattractcd.

t). The combination of a railway having a ruiming rail composed of magnetic and noninagnetic sections, a railway vehicle, a detector magnet carried by the vehicle and adaptedto be released by encountering a 1ioiiii'iiigiietic rail section and automatically attracted again on reaching a magnetic rail section, a circuit controlled by said magnet and havingr an electro-magnet, and ,a switch in said circuit actuated by said electro-magnet to hold the circuit closed.

l0. The combination of a railway having an armature rail, and magnet members mounted to travel above said rail and co- 'ol'ierating with opposite sides of the latter.

1l. The cmnbination of a` railway having Aan armature rail, and a magnet structure mounted to travel above said rail an( having pivoted pole-pieces coperating with opposite sides thereof.

1:2. The combination of a railway having an armature rail, a detector mounted to travel above said rail and having a ixid horizontalI magnet coil parallel with the rail, and a pivotal pole-piece having a core in said coil.

The combination ot a railway having an armature rail, and a detector mounted to travel above said rail and comprising a horizontal magnet coil, cores mounted to turn in ning the space above the rail.

,1i-1M The combination of a railway having an armature rail, a detector mounted t0 travel above said rail and comprising a lined horizontal magnet coil parallel with the rail, a hollow magnetic core mounted to turn in saidA coil and having liole-pieceslat its ends adziiited to be attracted toward said ,i said coil. and pole-pieces on said cores spancore mounted to turn in said hollow core and having pole-pieces at its ends adapted to be attracted toward said rail in the oppo site direction.

l5. rl'he combination of' a railway mag netically dilierentiated `at control points and having means at said points for obscuriiig the ditferentiation,a railway vehicle, magnetic devices thereon enacting with the railway, and indicating devices 4on the vehicle controlled by said `magnetic devices and adapted to give either a clear or a danger indication at said control points and a different indication between saidpoints.

1G. The combination of a railway having a running rail composed of magnetic and noirmagnetic sections, means on the roadway for magnetically by-nassinua noninagnetic section, a railway lvcliile, means on the vehicle for giving flange' and clear indications,` and magnet members on the vehicle so positioned as to be intluenced by said nonmmgnetic section and said 'bypassing means respectively, and ada ptcd to conjointlv give the danger indication when` the by-piissing means is inoperative, and the clear indication when the by-passing means is operative.

l?. The combination of a railway hav-- ing a running rail composed of magnetic and non-magnetic sections, means on the roadway for magnetically lay-passing a non-magnetic section, a railway vehicle, means on the vehicle t'or giving danger and clear indications, and magnet members on the vehicle so positioned as to beviniuenced by saidA non-magnetic section and said bypassing means icspectively, and adapted to give the danger indication when both of said magnet members are released and the clear indication when one is released and the other attracted.

1S. The combination of a railway having a running rail composed of magnetic andnon-magnetic sections, means for magneti cally by-passing a nonimignetic section, a

`railway vehicle, magnet members carried by said vehicle and adaiiited tc be attracted respectively by the magnetic sections ot the running rail and the bypassing means,

switches closed by the 'attraction of said members, a danger-indicating device carried `by the vehicle and 4iidapted to be operi'ited `by the ol'iening ofbotli of said switches, and a. clear-indicating device carried by the vehicle `and adapted to be'operated by the closing of the switch controlled by the' by l passing means "while the other switch is opened. 1 9. 'The combination ot a railway having "a"`;1jiinning rail composed ot magnetic Aand nonanagnetic sections, incarne for magnetically luy-passing a non-magnetic section, a

rail 'av vehicle, a detector carried by thef ica Viner independently iiii'ivablev pivoted pole- "vpieces, one ot' which is infiuenced bythe polepieces arereleased, and a clear-indi! fio eating device adapted to be actuated when the pole-piece controlled by the by-passingir means is att acted and the other released.

' 20.' The combination of a railway having a roadway armature, a vehicle on said railway, and a detector carried by said vehicle and comprising two magnet members ot' like polarity ,in repulsive relation to each i other, adapted to be attracted by said armaf ture.

' 21. The ycoiiibination of `a railway having' a roadway armature, a vehicle on said r railway, V and a detector carried by the vehicle and 'comprisinga stationary magnet coil and two cores mounted to vturn.therein and having pole-pieces of like polarity: iii repulsive relation to each other, adapted to be attracted toward said armature againstr the force of their repulsion.

A22. The combination of a railway having a roadway armature, and a detector mount edto travel over said armature and coinprising a magnet structure having independently-movable pole-pieces of' like polarity in repulsive relation andadapted to be attracted by said armature,l spring means for ,yieldingly retractiiig saidpole-pieces, andl adjustable stops for limitingtheirretractiye movement.

Q3. The combination of a railway having` a roadway armature structure, a vehicle on said railway, two magnet members on the vehicle cooperating with said armature structure, switches operated by said magnet members, a danger-indicating electro-niag-` electro-magnet on the vehicle whosevcirciiit -is controlled in parallel lby both' oi said net on the vehicle.y whose circuit is controlled in parallel by both of said switches, and a clear-indicating,r electron magnet on the vehicle in series with one ot the switches and with the;l first'said clectro-iiiagnet. i

24. ,'.The combination of a. railway having aroadwity armature, avehicle on said railway parallel circuits on said vehicle having, diii'erent resistances and including` clear and danger indicating' electro-magnets; and magnetic detector devices on the vehicle, cooperatinlg with said roadway armature and controlling said circuits.

25. The combination of a railway haijing' a roadii'ay armature structure, 'a vehicle on said railway` two magnet members on the vehicle, switches adapted to be yclosedy by the attraction ot' said magnet members toward i the ai'n/iature structurea daiiaeiiiidieating switches, a clear-indicating elcetro-iiiagnietl Von the vehicle in series with one ot' the switches and witlithe said danger-iiidcating electro-magnet, and a resistance oi? iess roadway armature devices, a vehicle on said railway,4 danger and clear indicators on said vehicle liavingz,T operating electro-magnets, an electromagnetl on the iehic-le :tor holding the clear-indicator in operati-ve position, a

switch operated by the lastesaid electro" magnet and controlling`- its circuit, and. de' l tector magnet members .carried by tlie vehicle and. responsive to said 'roadway armau tiire deyices for controlling 'the circuits said electroanagnets.

27.' The combination ota railway hai roadway armature devices, a vehicle on sind railway, detector magnet members carried by the vehicle2 switches closed by the at traction of said .magnet members toi 'ard the ,roadway armature devices, a danger-indieating electro-magnet carried by the vehicle and controlledy in parallel'by both et said switches, a elear-indicating `electromagriet on the rehicle iii-series with 'said dangew indicating electro-magnet and with one of said switches, an electroniagnet on the vehicle for retaining the clear indication, and a resistance whose resistivity is less than, that of said cleanindioating electro-magnet and greater than that ot' said retaining electrofniagnet, connected in shunt with the two last-said electro-magnets and in'series with the danger-indicating electro'-inagneti` 28; A railway having a running` rail comarising magnetic sections andan 'interposed non-magnetic section, a fixed magnetic baroverlapping` said`non-inagnetic sectionl andan adjacent magiic Qsectioni a movable magnetic bar alo'iitidev of id non-magnetio section, a vehicle on said riflway., a detector magnet carried by the vehicle and adapted to be attracted by said .iii'agnetic sectionsand released by said non-iiiafinetic4 section, a second detectorr magnet carried by the vehicle and adapted to be attract-ed by saidbars and, released when the movable bar is inoperative', and devices on the vehicle coii- .trolled by said detector magnets tor giving' danger and clear indications.

,f :29. The combination ot' a4 ailway having a! roadway armature structure and a sei-"ies of non-magnetic sections at control points, a. vehicle on said railway7 a plurality of niaglnetic detectors carried by the vehicle a'nd "capable, oic separate and conjoint action. `and an indicating device carried by the vehicle and operatedvby the coincident*release of said detectors'at a control point, but not' by the separate release of either detector.

rliti iso l 30. The combination ot' a railway having a iiiagiietc running rail interrupted by nony y u 1,193,773

magnetic Spctons, ehcle on said railway, set our hands 'in tlxe pl'esenc of two sub- 1U an ndctlmg device 4carried by the vehlcle, scribing witnesses, this (3th (luy of August,

a. plurality of detectolnmgnets carried by 1912.

the vehicile undlectrcnl swtchesvlosed by f T j tlxe aifftqction of Sndmngnets for the run IYFEDFROTH 11mg rml, the Openmg Vof both of said l J J 'switches being required tu uctlmte said n- Witnesses:`

dlcatlng devlc. u vl M. Pnmsux,

In testlmony whereof we have hereunto EDWARD E. BLACK. 

